Pneumatic drill.



No. 640,039. Patented Dec. 26, |899. C. T. SMITH & A. J. JOHNSON.PNEUMATIC DRlvLL.

(Application led Max. 18, 1899.) (No Model.)

2 Sheets-Sheet l.

C F e C Z l llls ANDREW .T. JOHNSON,

No. 640,039. Patented Dec. 25, [899. C. T. SMITH A. J. JOHNSON.

PNEUMATIG DRILL.

(Application filed Mar. 18, 1899.)

2 Sheets-Sheet 2.

(No Model.)

v INVENTUPTIS. CHHRLESTSNITH EY HNDREW I IOHNSQN.

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HTTET 1H: Noams Paises co4 vwofouwo., wAsmNa'raN u c UNITED STATESPATENT OFFICE.

CHARLES T. SMITH AND ANDREV J. JOHNSON, OF CLEVELAND, OHIO,

ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE CLEVELAND PNEU- MATIC TOOLCOMPANY, OF SAME PLACE.

vPNEUMATIC DRILL.

SPECIFICATION forming .part of Letters Patent No. 640,039, datedDecember 26, 1899.

Application filed March 18, 1899. Serial No. 709.658. (No model.)

To a/ZZ whom it may concern.-

Beit known that we, CHARLES T. SMITH and ANDREW J. JOHNSON, citizens ofthe United States, residing at Cleveland, in the county of Cuyahoga andState of Ohio, have invented certain new and useful Improvements inPneumatic Drills; and we do declare that the following is a full, clear,and exact description of the invention, which will enable others skilledin the art to which it appertains to make and use the same.

Our invention has reference to pneumatic drills; and the object of theinvention is to provide a drill with a series of associated powermechanism operatingin unison to drive the drill and supplementing oneanother in the application and increase of power, all substantially asshown and described, and particularly pointed out in the claim.

In the accompanying drawings, Figure l is a vertical sectional elevationof the drill on a line corresponding in lthe main to w Fig. 2,butleaving the gear unbroken. Fig. 2 is a plan view on line 2 2, Fig. l,the top being removed and disclosing a plan of the cylinders and theirfour several ports each. Fig. 3 also is a plan on line 3 3 of the wholemachine and designed to show the four several ports in the casingmatching those in the cylinders, as seen in Fig. 2 and as hereinafterfully described. Fig. 4 is a vertical sectional elevation on line 4 t,Fig. 8, showing one of the cylinders in section and its portsandconnections; and Fig. 5 is a vertical section on.

line 5 5, Fig. 3.

The object of the foregoing construction is to present a drill whichwhile it embodies all the propelling mechanism within itself and isself-equipped in all particulars for work yet is so compact andconvenient in the disposition of its parts that it can be placed andused in positions where,at the most,the room is limited and drills as.they ordinarily are constructed cannot be used at all.

To these ends we have adopted a form of casing A, which is nearly heartshape as viewed in plan and is just large enough to carry the operatingmechanism in the most advantageous arrangement that can be made and notwaste room. This mechanism comprises, flrst of all, a short crank-shaftB, set into suitable bearings in the removable side or top a of thecasing at one end and in the diaphragm or bottom a at the other end.

C is the tool or drill socket, having a spindle c working in the bushingc and arranged directly in line with the axis of shaft B.Antifriction-balls c2 are arranged between the head of the drill-socketand the flange of bushing c' to take the endwise thrust or pressure ofthe drill at work. This axial line of shaft and drill is the center ofthe machine, to which the other parts are built and operate.

The shaft B has a crank b at its center, and

on the shaft are a couple of counterbalaucesb opposite the crank b. Thehandles D and D are arranged axially opposite the center of the casing,so as to balance the machine thereon, and the handle D is a duct for thecompressed air to the distributing-chamber a2 in the casing,Fig.1,ashereinafter more fully described. Suitable valve mechanism also isconnected with this handle, whereby the flow of the air is easilymanipulated and governed, as will hereinafter appear.

Power is conveyed from the shaft B to the drill-socketn through a systemof gears arranged for power and confined in a suitable housing orsupplemental casing A', fixed removably to what for convenience isdescribed as the bottom of casing A. This gearing consists of the piniond on the lower extremity of shaft B, which meshes with large gearwheel don shaft F. On this shaft is a pini0n'd2, meshing with large gear d3 onthe inner or upper end of the spindle c of lfool-socket C. vThisarrangement of gears enables us to set lthe shaft B and socket C closetogether at their ends and at the same time obtain the advantage ofmultiplying the power on the socket several times.

Now in order to drive the foregoing mechanisrn pneumatically or with anykindred uid agent and get power for heavy and rapid work We employ aseries of engine-cylinders G and H, arranged substantially at rightangles to each other and supported each on trunnions centrally at theirsides, on which they are adapted to rock or oscillate as they operatetogether in driving the shaft B. Each cylinder has a sliding piston gand h, respectively, connected by their rods g' and 71. with the crankb, the rod 71. having a yoke h2, Fig. 5, adapted to engage crank b ateither side of rod g'.' By this arrangement of the power or motorcylinders G and H they follow each other in succession, and as onereaches the dead-center at either side of the stroke the other will beat its best in the stroke. Thus in Fig. 2 the dead-center is reached bythe motor-cylinder G and its piston and rod, with piston g at the end ofits stroke to the rear, while the cylinder His half-way in its strokeand in the place of greatest power on the crank-shaft B. Now followingthe parts a quarter-turn farther the cylinder H will be at the outerdead-center and cylinder G will be at its best,'with its piston g on thehalfstroke. This change occurs four times, or at every quarterturn, inevery revolution of shaft B, and it is pushand pull alternately in eachcylinder, the inlet and exhaust for each being so arranged that themotive agent enters first on one and then on the other side of thepistons. How this occurs may now be traced in the drawings. Assumingthat we are operating compressed air, though any expansible Huid may beused that will do the work, the said fluid or air enters through tubularhandle D into distributing-chamber d2, Fig. 1,common to bothmotor-cylinders. From this chamber ducts g3 and 71.3 lead to the twocylinders G and H, respectively, and enter the cylinders through twoseparate ports 2 and 3 and exhaust through two like ports 4 and 5. Thecylinders each have inlet-ports 6 and 7 to match 2 and 3 andoutlet-ports 8 and 9 to match 4 and 5. The oscillation of the cylindersis utilized as a medium for opening and closing the said ports, and inthe disposition of the ports as shown 2 and 6, 3 and 7, 4 and 8, and 5and 9 go together. Hence it occurs that when one set of inlets is openone of the exhausts also is open and the other set of inlets andexhausts is closed. This is demonstrated in Fig. 3 and thecross-section, Fig. 5. The motive iuid enters through ports 3 7, behindpiston h, and exhausts through ports 4 8. When the piston reaches thefarther limit of its stroke, both these sets of ports will be closed andthe opposite sets 2 6 and 5 9 will be opened, and so on alternately. Forsimplicity we use the same referenceiigures for the ports connected withboth cylinders, because the operation is identical in both.

It will be noticed as a feature peculiar to this construction that theexhaust-ports have their exit at the series of openings 8', to whichboth exhaust-ports for cach power-cylinder lead. Hitherto all dischargeshave been internally, where all the dust and dirt in the air wouldnaturally accumulate and foul the operating mechanism. Our dischargesare.

outside, and the interior of the machine is atmospherically closedagainst the admission of dust from any source.

An important oce of the housing A is its affording a perpetuallubricating-chamber for the contained gearing, thus preventingoverheating under the excessive friction a tool of this kind is subjectto when under the usual strain. For example, the present tool weighstwenty-one pounds, and yet will bore an inch-and-a-half hole over aninch in depth in solid steel in less than a minute. The tool has to becrowded to do this, and hence will heat at once if no precaution betaken to prevent it. so tight that the usual grade of lubricant will besealed up therein and in such quantity that the gearing cannot do morethan get warm and never heats; but such rapid work would be impossiblewith this tool without these lubricating facilities. The same conditionas to lubricants holds true of the mechanism within the casing A, and inboth chambers the mechanism is constantly flooded with oil.

It will be noticed that the cylinders have each on their top a flatsurface or portion matching the corresponding surface of the main casingand the respective ports or ducts for the power fluid are through theseflat closely-matched surfaces or portions for both inlet and exhaust.The casing is shown as somewhat recessed to receive the flat portion ofthe cylinder, so as to make a very close [it at this point and avoidperceptible leakage. It will also be Vobserved that the ports are soarranged and the cylinders so constructed as to themselves control theports, thus avoiding all necessity for valve mechanism for either inletor exhaust passages.

What we claim is- In an oscillating engine, in combination with a maincasing, and a fluid-pressure-supply chamber, a pair of oscillatingcylinders, two series of inlet and exhaust ports in each cylinder,correspondingv inlet-ports in said supply-chamber, ducts leading fromsaid cylinder inlet-ports to opposite sides of the piston, means tosimultaneously open'one series of ports and close the other by theoscillation of the cylinder, an independent exhaustchamber common toboth of said cylinder exhaust-ports, ducts leading from saidexhaust-ports to said chamber, and ducts leading from said chamber andhaving exits exterior the casing, substantially as described.

Witness our hands to the foregoing specication this 27th day ofFebruary, 1898.

CHARLES T. SMITH. ANDREW J. JOHNSON.

Witnesses:

H. T. FISHER, R. B. MOSER.

The housing A is designed to be' IOO IIO

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